Guide rail for a gantry system

ABSTRACT

A guide rail for a gantry system includes a support structure having an elongated support surface and a plate having a precision surface relative to the elongated support surface. A filler material bonds the plate to the elongated support surface. The filler material can have a varying thickness along the elongated support surface to maintain a desired orientation of the plate. A method of constructing the same is also provided.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to gantry systems. In more particular, the present invention relates to a guide rail and a method of making the same for a gantry system.

[0002] Gantry systems are well known and commonly used in tooling, machining or positioning systems. Generally, the gantry system includes two spaced apart rails. A bridge extends between the rails and travels thereon. A mast is coupled to the bridge. The mast supports milling tools, lifting devices and sensors of the like. Typically, the mast is moveable along the bridge and telescopes in order to provide three degrees of freedom, while an end effector mounted at the end of the mast can provide additional movements.

[0003] Guide rails for gantry systems are expensive to manufacture. Commonly, each guide rail is welded from a number of components. The bulky weldment then must be machined to form a mounting surface suitable for guiding elements of the guide rail. In many cases, the guide rail must be sent to a remote location for machining. Thus, besides the machining cost, significant transportation cost are also incurred.

[0004] An improved guide rail for a gantry system that is easier and/or cheaper to manufacture is therefore needed.

SUMMARY OF THE INVENTION

[0005] A guide rail for a gantry system includes a support structure having an elongated support surface and a plate having a precision surface relative to the elongated support surface. A filler material bonds the plate to the elongated support surface. The filler material can have a varying thickness along the elongated support surface to maintain a desired orientation of the plate on the support structure.

[0006] Another aspect of the present invention is a method for constructing a guide rail. The method includes orienting a guide surface of a plate to face downwardly; holding the support structure above and spaced apart from an upwardly facing surface of the plate; and disposing a bonding material between the upwardly facing surface and the support structure to fill a gap therebetween, wherein the bonding material solidifies.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 is a side view of a gantry system.

[0008]FIG. 2 is a front view of the gantry system.

[0009]FIG. 3 is a front view of a portion of the gantry system.

[0010]FIG. 4 is a front view of a fixture for forming a guide rail.

[0011]FIG. 5 is an exploded perspective view of the fixture.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0012] Referring to FIGS. 1-2, a gantry system is illustrated at 11. Gantry system 11 includes a pair of spaced apart rails 13. In the exemplary embodiment, rails 13 are elevated, being supported by supports 16. Bridge 10 spans between rails 13. Two trucks 14 are coupled to bridge 10 and coupled to rails 13 in order to provide horizontal movement of bridge 10 in a direction parallel to axis 41 as is well known in the art. Bridge 10 supports a mast 12, which is adapted to hold an end effector 18 such as a tool, lifting device, sensor or the like. Bridge 10 can be adapted to allow movement of mast 12 along bridge 10 parallel to the direction of axis 43. In the embodiment illustrated, mast 12 comprises a telescoping assembly in order to allow end effector 18 to move in a direction parallel to axis 45. Typically, axes 41, 43 and 45 are orthogonal to each other, thereby allowing three-dimensional movement of the end effector 18.

[0013] At this point, it should be noted that the design of the trucks 14, which allows movement of the bridge 10 on the corresponding rails 13, does not form part of the present invention and can take any of many known forms. Similarly, the design of the mast 12 and bridge 10 are also not part of the present invention and can take any of many known forms.

[0014] Referring to FIG. 3, each guide rail 13 supports a guiding element 50 such as a linear bearing, that in turn, supports truck 14 and mast 12 connected thereto. A drive assembly 51 is also commonly provided to drive each truck 14 relative to guide rail 13. For instance, drive assembly 51 can include a drive motor 53 and pinion gear 55 that are mounted to at least one of the trucks 14. As illustrated in FIG. 3, a linear gear rack 52 is provided on rail 13 extending along the length thereof. Gear 55 engages linear gear rack 52 and with operation drive assembly 51 will displace truck 14 along rail 13.

[0015] As discussed in the background section, it is necessary to provide a precision surface on rail 13 such that the guiding elements, herein linear bearing 50, is accurately positioned along the length of the rail 13 to ensure proper operation of the gantry system 11. Typically, however, current techniques require precision machining in order to obtain a suitable mounting surface, which complicates manufacturing and increases cost.

[0016] Guide rail 13 of the present application is simpler and cheaper to manufacture. Generally, guide rail 13 includes a support structure 60 having an elongated support surface 62 and a plate 64 having an upper surface 66 that is more precisely formed than that of the elongated support surface 62. A filler material 70 is disposed between a lower surface of the plate 64 and the elongated support surface 62. The filler material 70 bonds the plate 64 to the support structure 60. Typically, the filler material 70 fills a gap between the plate 64 and the support structure 60 that has a varying thickness along the elongated support surface 62 in order to maintain a desired orientation of the plate 64.

[0017] Support structure 60 can take any of a number of known forms. For instance, the support structure 60 can comprise a wide-flange beam (herein illustrated), an I-beam, a box-like structure, just to name a few. Generally, the support structure 60 need only provide the elongated support surface 62. However, the elongated support surface 62 need not be a precision surface in that elongated support surface 62 can vary in height along a length of the support structure 60, and can even include some twisting.

[0018] Unlike support structure 60, plate 64 includes at least one planar surface 66 that will be used to support the guide elements thereon. Such plates can be readily purchased as a stock item, or can be machined, if desired, to have a precision surface 66. However, unlike the bulky weldments of guide rails discussed in the background section of the present application, machining of plate 64 is relatively easy.

[0019] Filler material 70 bonds support structure 60 to plate 64 and is generally non-compressive when solidified. Other desirable characteristics of filler material 70 include non-shrinking during solidification. Filler material 70 can be a liquid or a gel. An epoxy is a specific example of a suitable material.

[0020]FIGS. 4 and 5 illustrate a fixture 100 and a method of making guide rail 13. Generally, fixture 100 includes a support base 102 having an upper surface 104 that is precision machined to be flat and true. In the embodiment illustrated, cross beams 106 are provided to support base 102 to provide a stable structure.

[0021] Upon surface 104, plate 64 is placed thereon with precision surface 66 facing downwardly. Thus, surface 66 is kept planar with respect to surface 104. Filler material 70 can then be disposed on plate 64 with support structure 60 placed thereon. Filler material 70 will fill any gaps between plate 64 and support structure 60 and bond each together.

[0022] In a further embodiment, spacers 105 are provided between plate 64 and support structure 60 to control the gap therebetween and ensure that a sufficient quantity of filler material 70 is provided to effectuate bonding. In yet a further embodiment, the height of the spacers 105 are adjusted such that a gap is present along the entire length of the plate 64 or support structure 60 such that surfaces 66 and 104 do not contact each other.

[0023] Spacers 105 can take many forms such as blocks, rods or the like. In the embodiment illustrated, each spacer comprises a threaded bolt that extends through a threaded aperture in the support structure 62 such that an end of the bolt 105 contacts plate 64 and holds or supports support structure 60 above plate 64. Individual rotation of the bolts increases or decreases the height of support structure 60 over plate 64. In one embodiment, two bolts 105 can be provided at each end of support structure 60. The bolts 105 are adjusted to ensure that a gap is present along the entire length of the support structure 60, and/or adjust the relative orientation of the upwardly facing surface of the support structure 60. Additional bolts 105 can be used if necessary to control beam sag.

[0024] After the height and/or orientation of support structure 60 relative to plate 64 has been obtained, filler material 70 is disposed between plate 64 and support structure 60. The method of construction can include lifting the support structure 60 off of plate 64 and applying filler material 70 to plate 64. Depending on the viscosity of filler material 70, a temporary dam structure can be created on plate 64 to contain filler material 70. Support structure 60 can then be lowered upon plate 64 wherein the spacers 105 (herein bolts attached to support structure 60) holds support structure 60 over plate 64 during solidification of filler material 70, wherein a sufficient amount of filler material 70 has been extruded between plate 64 and support structure 60 in order to ensure sufficient contact.

[0025] Referring back to FIG. 3, guide rail 13 with plate 64, filler material 10, and support structure 60 can be secured in place upon the gantry system, for instance, on support 16. Typically, adjustable mounting assemblies 101 are provided between support structure 60 and support 16 to ensure proper leveling of guide rail 13.

[0026] It should be noted, in some applications that it may be necessary to form rail 13 from separately subassemblies, each subassembly being constructed in a manner discussed above. In such cases, plates 64 can include precision recesses 107 (FIG. 4) on ends thereof that when aligned with respect to each other receive splines 109 (FIG. 5) to ensure proper alignment of the subassemblies.

[0027] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. 

What is claimed is:
 1. A guide rail for gantry system, the guide rail comprising: a support structure having an elongated support surface; a plate having a precision surface relative to the elongated support surface; and a filler material bonding the plate to the elongated support surface, the filler material having varying thickness along the elongated surface to maintain a desired orientation of the plate.
 2. The guide rail of claim 1 wherein the filler material comprises a flowable material that later forms a solid body.
 3. The guide rail of claim 2 and further comprising a plurality of spacers to support the plate from the elongated support surface prior to application of the flowable material.
 4. The guide rail of claim 3 wherein each of the spacers are adjustable in length.
 5. The guide rail of claim 4 wherein each of the spacers comprise a threaded bolt.
 6. The guide rail of claim 5 wherein each threaded bolt engages a threaded aperture in the support structure.
 7. The guide rail of claim 2 wherein the flowable material comprises an epoxy.
 8. A gantry system comprising: a pair of spaced apart guide rails, each guide rails comprising: a support structure having an elongated support surface; a plate having a precision surface relative to the elongated support surface; and a filler bonding the plate to the elongated support surface, the filler material having varying thickness along the elongated surface to maintain a desired orientation of the plate; and a bridge movable on the guide rails.
 9. The gantry system of claim 8 wherein the filler material comprises a flowable material that later forms a solid body.
 10. The gantry system of claim 9 wherein each guide rail includes a plurality of spacers to support the plate from the elongated support surface prior to application of the flowable material.
 11. The gantry system of claim 10 wherein each of the spacers are adjustable in length.
 12. The gantry system of claim 11 wherein each of the spacers comprise a threaded bolt.
 13. The gantry system of claim 12 wherein each threaded bolt engages a threaded aperture in the support structure.
 14. The gantry system of claim 9 wherein the flowable material comprises an epoxy.
 15. A method for constructing a guide rail, the method comprising: orienting a guide surface of a plate to face downwardly; holding a support structure above and spaced apart from an upwardly facing surface of the plate; and disposing a bonding material between the upwardly facing surface and the support structure to fill a gap therebetween, wherein the bonding material solidifies.
 16. The method of claim 15 wherein disposing includes flowing the bonding material into the gap.
 17. The method of claim 15 wherein holding includes locating a plurality of spacers between the support structure and the plate.
 18. The method of claim 17 wherein locating includes adjusting a length of each of the spacers.
 19. The method of claim 18 wherein each of the spacers comprises a threaded bolt.
 20. The method of claim 19 wherein each of the bolts extends through a corresponding threaded aperture in the support structure.
 21. The method of claim 16 and further comprising forming a dam to define a boundary of the flowable material. 